In a cladogram depicting the evolutionary relationships among amphibians, reptiles, birds, and mammals, Group IV is the most derived group. Which of the following species is most likely included in Group IV?

• A. Homo sapiens (humans)
• B. Gallus gallus (chicken)
• C. Testudo graeca (Greek tortoise)
• D. Rana temporaria (common frog)

Answer: (A)

Verified step by step guidance

1. Understand the concept of a cladogram: A cladogram is a diagram that shows evolutionary relationships among species based on shared derived traits. The most derived group in a cladogram represents the species that have evolved the most traits distinct from the ancestral group.
2. Identify the species listed in the problem: Homo sapiens (humans), Gallus gallus (chicken), Testudo graeca (Greek tortoise), and Rana temporaria (common frog). These species belong to different taxonomic groups within the vertebrates.
3. Determine the evolutionary relationships: Amphibians (e.g., Rana temporaria) are the least derived group, as they are among the earliest vertebrates to transition to land. Reptiles (e.g., Testudo graeca) evolved later, followed by birds (e.g., Gallus gallus), which are more derived due to adaptations like feathers and flight. Mammals (e.g., Homo sapiens) are the most derived group, characterized by traits such as hair, mammary glands, and advanced brain development.
4. Analyze the traits of Group IV: Since Group IV is described as the most derived group, it would include species with the most advanced evolutionary traits. Among the listed species, Homo sapiens (humans) exhibit the most derived characteristics, such as complex brain function, upright posture, and advanced social structures.
5. Conclude the reasoning: Based on the evolutionary relationships and derived traits, Homo sapiens (humans) are the species most likely included in Group IV of the cladogram.